#257CD4
Closest named color: Windows Blue (#3778BF). oklch(58.2% 0.157 252.7), rgb(37, 124, 212).
Aa
Black text reads best on this color (4.91:1).
About this color
#257CD4 is a medium-dark, vivid blue. In OKLCH its lightness is 58%, its chroma 0.157 and its hue 253°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.033 away. Black text reads best on it, at 4.91:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | vivid (0.157) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.91:1 |
| White text | 4.27:1 |
Values
| HEX | #257CD4 |
| RGB | rgb(37, 124, 212) |
| HSL | hsl(210, 70%, 49%) |
| OKLCH | oklch(58.2% 0.157 252.7) |
Contrast
WCAG 2 contrast ratios are the conformance target: AA needs 4.5:1 for body text and 3:1 for large text, AAA needs 7:1. APCA Lc values are supplementary guidance from the WCAG 3 drafts.
| Pair | WCAG 2 | Result | APCA | APCA guidance |
|---|---|---|---|---|
| White text on #257CD4 | 4.27:1 | AA large text | Lc -74.6 | Content text, not long reading |
| Black text on #257CD4 | 4.91:1 | AA | Lc 35.0 | Non-text elements, placeholder text |
| #257CD4 text on white | 4.27:1 | AA large text | Lc 69.1 | Content text, not long reading |
| #257CD4 text on black | 4.91:1 | AA | Lc -32.6 | Non-text elements, placeholder text |
Tints and shades
A 50–950 scale built in OKLCH: the hue is held, lightness follows a Tailwind v4-like curve, and every step is kept inside the sRGB gamut. This color sits at step 600.
-
Step 50
50
#F1F6FC
oklch(97.1% 0.01 252.8)
-
Step 100
100
#E1EBF8
oklch(93.6% 0.021 254.9)
-
Step 200
200
#C7DBF3
oklch(88.4% 0.04 253)
-
Step 300
300
#A0C4EE
oklch(80.9% 0.071 252.6)
-
Step 400
400
#6CA4E5
oklch(70.7% 0.113 253)
-
Step 500
500
#418CDE
oklch(63.2% 0.145 252.8)
-
Step 600
600 (this color)
#257CD4
oklch(58.2% 0.157 252.7)
-
Step 700
700
#0961B0
oklch(49.1% 0.146 252.7)
-
Step 800
800
#0F4F8E
oklch(42.6% 0.121 252.9)
-
Step 900
900
#164372
oklch(37.8% 0.094 252.5)
-
Step 950
950
#0E2743
oklch(26.9% 0.061 253.2)
#257CD4 with color blindness
Simulated with the Machado et al. (2009) model. ΔE is how far the color moves: below about 0.02 you would not notice a change.
| Vision | Seen as | Shift (ΔE) |
|---|---|---|
| Protanopia (no red cones) | #5083D7 | 0.041 |
| Deuteranopia (no green cones) | #3173D2 | 0.024 |
| Tritanopia (no blue cones) | #00919D | 0.117 |
| Achromatopsia (no color) | #7A7A7A | 0.157 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #257CD4
#257CD4
oklch(58.2% 0.157 252.7)
- #A76D00
#A76D00
oklch(58.2% 0.124 72.6)
Analogous
Neighbouring hues, 30° either side.
Split complementary
The two hues beside the complement (150° and 210°).
Triadic
Three hues spaced 120° apart.
Palettes with this color
Curated palettes that contain a color within ΔE 0.04 (OKLab) of #257CD4, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.033
- Water Blue #0E87CC ΔE 0.035
- Royal Blue #4169E1 ΔE 0.056
- Nice Blue #107AB0 ΔE 0.058
- Cerulean Blue #056EEE ΔE 0.059
- Cool Blue #4984B8 ΔE 0.059
- Dark Sky Blue #448EE4 ΔE 0.059
- Steel Blue #4682B4 ΔE 0.060
Use #257CD4 in your product
Turn it into light and dark UI roles checked for contrast, then export to Tailwind v4, shadcn/ui, CSS or design tokens.